Trip mechanism for dumping buckets



Oct. 12, 1937. I J. A. ELMES 2,095,322

\ TRIP MECHANISM FOR DUMPING BUGKETS Filed Jan. 13, 1937 2 Sheets-Sheet l INVENTOR ATTORNEYS Oct.l2, 1937. J. A. ELMES TRIP MECHANISM FOR DUMPING BUCKETS Filed Jan. l5, 1937 2 Sheets-Sheet 2 INVENTOR ATTORNEYS s==== ME W Patented (Jam, 1937 PATENT orrice TRIP MECHANISM FOR, DUMPING BUCKETS .iohn A. Elmes, Beaver Falls, Pa.,-. assignor to Keystone Driller Company, Beaver Falls, Pa, a corporation vof Pennsylvania "Application January 13, 1937, Serial No. 120,423

7 Claims.

This invention relates to an excavating machine and more particularly to an improved trip mechanism for releasing the latch which holds the bottom or door of a bucket or scoop for the purpose of enabling the'same to discharge its load;

The object of this'invention is to provide a latch releasing mechanism of this character which is strong and durable and not liable to get out of order when subjected to rough usage, which will promptly and reliably release the bottom regardless of the size of the load which is carried thereon, and which is compact in construction and capable of being applied to the standard forms of scoops now on the market;

In the accompanying drawings- Fig. 1 is a fragmentary rear elevation of an excavating scoop, bucket or shovel equipped with the bottom releasing mechanism embodying this invention.

Fig. 2 is a side elevation of the same.

Fig. 3 is a fragmentary vertical longitudinal sectionv of the same, on a reduced scale, taken on line 33, Fig. 1. t e y 7 Fig. 4 is a horizontal section, taken on line 4- -4, Fig. 1.

Fig. 5 is afragmentary side View of the co.-

operating cam parts of the catch and the trip lever forming part of the bottom releasing mechanism.

Fig. 6 is a section, on an enlarged scale, taken on the correspondingly numbered line in Fig. 1,

Fig. 7 is a fragmentary perspective view of the detent mechanism whereby the switch in the electric circuit of the operating electric motor is held open.

"In the following description like characters of reference indicate like parts in' the several figures of the drawings.

Although this trip mechanism may be used to advantage in scoops, buckets or shovels of various kinds that are shownin the drawings. as an example of one suitable for this purpose is open at the top and at the fro'nt'andcomprises a body having an upright back or transverse rear wall IB and two upright longitudinalsides or walls l i extending forwardly from the back wall, and a bottom or lower horizontal door l2 engaging the lower' edges of the back and side walls and pivoted at its front end to the side walls by horizontal transverse pivots 53 so that the rear part of the bottom can swing vertically into an open and closed position. At its front end the bottom is provided with the usual digging teeth M for engaging the the scoop. The rear end of the bottom may be held in its operative position across the lower side of the body by a releasable latch mechanism which may be of any suitable construction, that shown in the drawings being satisfactory and constructed as follows: 1

being pivoted by a horizontal transverse pin H).

on the ribs of a bracket projecting rearwardly from the back wall of the scoop body, as best shown in Figs. 1 and 3. The catch is yieldingly held in its forward position by a spring 2| interposed between the rear side of the catch and the 'front side of an abutment 22 depending from a cross bar 23 on the bracket ribs 28, said spring in this instance being of helical form and surrounding a horizontal pin 2twhich is connected at its rear end with the'abutment and rests at its 7 front end in an opening 25 in the rear wall In, while its intermediate'part extends through an openinglli in the adjacent part of the catch, as best shown in Figs. 3 and 4. Upon moving the catch rearwardly its nose is disengaged from the keeper of the bottom, thereby permitting the latter to drop by gravity and discharge its load and during the subsequent upward return swing of the bottom its keeper is again automatically caught by the catch and held in its closed position.

The latch releasing mechanism whereby the catch is disengaged from the keeper for permitting the bottom to open in accordance with this invention is preferably constructed as follows:-

The numeral 21 represents a trip arm which is the cams 28, 29 engage with each other, as shown in Fig. 5, and permit the catch to move forthe trip arm is turned anti-clockwiseits cam 28 rides up on to the high parts of the cam 29 on the catch thereby moving the latter rearwardly and disengaging the same from the keeper and re-' leasing the bottom.

wardly for holding the bottom closed, but when The numeral represents a gear segment arranged in rear of the back wall of the scoop body and pivotally supported thereon so as to turn vertically in a plane transverse of the scoop by means of a pivot consisting preferably of a horizontal bolt 3! passing through the lower part of the segment and secured at its front end to the rear scoop wall. The teeth of the segment are preferably on its upper part and on its lower part the same is provided with a crank or arm 32 projecting downwardly from the axis of the segment. An operative connection between the segment and the trip arm is produced by an upright link 33 which is pivoted at its upper end by a pin 34 to the crank 32 while its lower end is pivotally connected by a pin 35 with the outer end of the trip arm, as best shown in Fig. 1. When the bottom is closed the gear segment has been turned anti-clockwise into its fully retracted or rearmost position, as shown in Fig. 1, and the same is yieldingly held in this position by a spring 36, preferably of the helical type, which is connected at its upper end with the pivot pin 34 while its lower end is connected with a part of the rear wall of the scoop, such as a guard bracket 37 projecting rearwardly from this wall, as shown in Figs. 1 and 2.

For the purpose of positively limiting the extent of the oscillating movement of the gear segment and its crank, stop means are provided which preferably consist of a front stop block 38 of rubber adapted to be engaged by the front side of the segment and a rear stop block 39 adapted to be engaged by the rear side of the crank arm 32, these stops being secured to the rear side of the rear scoop wall by a retaining plate 49 overlapping both of these stops and screws M connecting this plate with said wall, as shown in Figs. 1 and 2. By constructing these stops of rubber or similar material the same not only limit the movement of the segment and the parts operatively connected therewith but they also render the working of the same practically noiseless.

Above the segment is arranged an interme diate gear wheel 42 which meshes with the gear teeth on the upper part of the segment and which preferably has a radius of one-half that of the segment. This intermediate gear wheel is pivoted by a bolt 43 on a housing M mounted on the upper part of the scoop body and the same is rotated by a driving gear pinion 45 meshing with the upper part thereof and having a radius. of one-third of that of the intermediate gear wheel. This driving pinion may be rotated by a motor of any suitable character but it is preferable to employ for this purpose an electric motor 656 which is supported in the housing M and has its driving shaft tl secured to the driving pinion 45, as shown in Figs. 1 and 2.

Upon operating the motor by closing its circuit the driving pinion 45 turns clockwise, as indicated by the arrow associated therewith in Fig. 1, the intermediate gear wheel is turned anti-clockwise and the gear segment is turned clockwise, thereby causing the crank 32 to be raised and the trip arm 2? to be turned anti-clockwise and thus operate the latch mechanism for releasing the bottom of the scoop. Upon breaking the circuit of the motor its driving pinion t5, the intermediate gear wheel segment and parts operatively connected therewith are turned in the opposite direction.

Means are provided for opening and closing the circuit of the motor which include a a manually operable switch device for closing the circuit of the motor when it is desired to operate the latch releasing mechanism and also an automatically operable switch device, whereby this circuit is opened when the motor has turned forwardly sufficiently to effect this operation and this circuit is again closed when the motor has turned backwardly to its starting position. The preferred means for this purpose shown in the drawings are constructed as follows:

The numerals 2 8, 49 represent the stationary and movable contacts of an automatically operable switch for opening and closing the motor circuit, which contacts are preferably constructed in the form of rivets, as shown in Fig. 6. The stationary contact is arranged below the intermediate gear wheel and mounted on a bracket 50 secured to the adjacent part of the rear scoop wall but insulated from said bracket by a bushing 5! of rubber or the like. The movable switch contact 69 is carried toward and from the fixed contact t8 by a switch lever 52 to which it is secured between the upper and lower ends of this lever. At its lower end the switch lever is pivoted by a pin 53 and this lever is constantly urged in the direction for engaging the contact thereon with the stationary contact by a helical spring 54 interposed between the switch lever and a sup porting bracket 55 on the rear scoop wall, this spring being held against displacement by a retaining pin 55 passing through this spring and secured at its outer end to the supporting bracket and projecting at its inner end into an opening 5? in the switch lever, as shown in Fig. 1. At its upper end the switch lever is provided with a laterally projecting lug 58 which forms an inwardly facing shoulder thereon and between its contact and its lower end this lever is provided on its inner side with a cam surface 59. On the front part of the rear side of the gear segment the same is provided with a rearwardly projecting tappet or cam 63 having a rounded face which is adapted during the forward movement of the segment to engage the cam face 59 of the switch lever and tum the latter so as to separate the switch contacts 48, 49, and during the backward movement of the segment to permit said lever to again engage its contact with the stationary contact. The numerals 6!, 62 represent the upper releasing arm and the lower catch arm of a detent lever which is pivoted by a pin 63 on the rear scoop wall adjacent to the intermediate gear wheel. The lower catch arm has the form of a hook, the mouth 64 of which opens upwardly and the inner end of which has an inclined face 65 arranged below the retaining lug 58 of the switch lever. At its upper end the releasing arm 61 is provided with a wiping face 66 which is adapted to be engaged by a curved releasing cam 6'! pro-- jecting from the rear side of the intermediate gear wheel. Resilient means tending constantly to turn the detent lever in a clockwise direction are provided, which means preferably consist of a spring 68 connecting the releasing arm 6! with the adjacent stationary part of the machine, such as the housing for the motor and adjacent parts.

The electric current for driving the motor may be derived from any suitable source which is conventionally represented in the drawings as consisting of a battery 69. This battery is included in a circuit which contains the automatic switch contacts '58, 59 and also a manually operable switch iii, as shown in Fig. 1.

Fig. 1 shows the parts in the position which they occupy when the bottom is held shut by the latch mechanism, the contacts 48, 49 of the auto- V V 2,095,322 matic switch are closed, thereleasing camtl'is gear segment pivoted on said scoop to oscillate holding the detent lever in a position in which its hook is away from the lug 58 of the switch lever,

and the manually operable switch Ill and the motor is at rest in its startingposition.

Whenit is desired to release the latc'h'mechanism'for dumping the load from the scoop'or forother purposes the attendant. closes the hand switch 1D,.thereby closing the circuit which includes the motor and the batteryyso that the motor pinion and gear segment turn clockwise, and the intermediate gear wheel turns anticlockwise, whereby the latch mechanism is released andthe scoop bottom permitted to drop.

During the last part of the forward or clockwise movement of the gear segment the releasing cam or tappet 60' on the gearsegment engages the cam surface 59 on the switch 'lever and pushes the same outwardly whereby the movable contact 49 carried thereby is ca'rrie'daway from the fixed contact 43 and the circuit of the motor is opened regardless of Whether the attendant is still holding the manual switch '10 in a closed position, whereby the motor ceases to turn forwardly. During the first part of the anti-clockwisermovement of the intermediate gear wheel its cam 61 is moved away from the releasing arm 6| of the detent lever so as to permit the spring to turn the lever clockwise and engage the inclined face 65 of the detent hook with the underside of the lug 58. When the tappet or cam 60 therefore subsequently moves the switch lever outwardly the lug 58 of the latter is automatically caught in the mouth 64 of this hook by the action of the spring 68 which turns the detent .lever clockwise at this time and holds the automatic switch in its open position. During the return or backward movement of the segment under the action of the return spring 36 the tappet or cam 60 moves away from the switch lever and during the last part of the return or clockwise movement of the intermediate gear wheel its cam 61 engagesthe cam face 66 of the releasing arm of the detent lever and turns the latter so that its catch arm 62 is disengaged from the lug or shoulder 53 of the switch lever, thereby permitting the spring 54 to move the switch lever inwardly and reengage the contacts-48, 49 preparatory ,to beginning the next cycle of operations of this mechanism. 7 l V It is, of course, assumed that the attendant will let go of the manual switch or permit the same to open after the scoop has been dumped so as to permit the automatic switch mechanism to operate in the manner described.

. By making the intermediate gear wheel of shorter radius than that of the gear segment it is possible to readily time the action of the cams 60 and 61 so that the cam 61 will permit the detent lever to assume a position for interlocking with the switch lever 59. when the latter is subsequently moved outwardly by the cam 60 of the gear segment and it also permits the cam 60 to clear the switch lever 52 so that spring 54 can move the switch lever into its closed position the instant that the cam 61 of the intermediate gear wheel during the subsequent return movement of the same operates to withdraw the detent lever from the switch lever.

I claim as my invention:---

1. In an excavating machine, a scoop having a body and a bottom pivotally mounted on the body; a latch device for holding saidbottom in its closed position, and means for operating said latch device to release said bottom comprising a thereon and operatively connected with said latch device, an electric motor geared to said segment, and an electric switch arranged in the circuit of said motor and adapted to be opened while said segment is effecting the last part of itsforward-movement and operating the latch device to release the bottom andalso adapted to be closedduringthe-last part of the backward movement of said segment. i 2. In an excavating machine, a scoop having a body and a bottom pivotally mounted on the said segment has operated the latch to release."-

said bottom, and stop means for limiting the oscillating movement of said segment;

13. In an excavating machine, a scoop having a body, and a bottom pivoted .on the body; a latch device for holding the bottom in its closed position, and means for operating said latch device 'to release the bottom comprising an oscillating gear segment pivoted on said body and having a rock arm which is operatively connected with said latch device, an electric motor geared to said segment and adapted to move the same forwardly.

for releasing said latch device, a'spring operatively associated with said segment for turning the same backwardly, and an electric switch which is arranged in the circuit of said motor and which is opened during the last part of the forward movement of the segment and closed during the first part of the backward movement of the same.

4. In an excavating machine, a scoop having a body, and a bottom pivoted on the body; a latch device for holding the bottom in its closed position including a keeper on the bottom, a catch pivoted on the body and adapted to engage said keeper anda spring for moving said catch toward said keeper, and means for releasing said catch from the keeper including a cam lever having a cam engaging said catch, a gear segment having a crank arm, a link connecting said crank arm with said cam lever, a spring for turning said segment backwardly, and an electric motor geared to said segment and adapted to turn the segment forwardly.

5. In an excavating machine, a scoop having a body and .a bottom pivotally mountedon the body; a latch device for holding said bottom in its closed position, and means for operating said latch device to release said bottom comprising a gear segment pivoted on said scoop to oscillate thereon and operatively connected with said latch device,

segment, an electric motor having a gear pinion meshing with said intermediate gear wheel, an electric switch arranged in the circuit of said motor, means for causing the forward movement of said segment to open said switch, a. detent devicefor holding the switch in its open position, and means for causing the backward movement of said intermediate gear Wheel to close said switch.

6. In an excavating machine, a scoop having a body and a bottom pivotally mounted on the body; a latch device for holding said bottom in its closed position, and means'for operating said latch device to release said bottom comprising a gear segan intermediate gear wheel meshing with said a ment pivoted on said scoop to oscillate thereon and operatively connected with said latch device, an intermediate gear wheel meshing with said segment, an electric motor having a gear pinion meshing with said intermediate gear wheel, an electric switch arranged in the circuit of said motor and having a stationary contact and a movable contact adapted to engage with the stationary contact, a rocking switch lever pivoted on said body and carrying said movable switch contact, a spring for moving said switch lever toward the movable contact, a cam on said segment adapted to engage said switch lever and move the same away from said stationary contact, a holding device for holding the switch lever away from said stationary contact, and a cam on said intermediate gear which is adapted to release said holding device from said switch lever.

'7. In an excavating machine, a scoop having a body and a bottom pivotally mounted on the body; a latch device for holding said bottom in its closed position, and means for operating said latch device to release said bottom comprising a gear segment pivoted on said scoop to oscillate thereon and operatively connected with said latch device, an intermediate gear wheel meshing with said segment, an electric motor having a gear pinion meshing with said intermediate gear wheel, an electric switch arranged in the circuit of said motor and having a stationary contact and a movable contact adapted to engage with the stationary contact, a rocking switch lever pivoted on said body and carrying said movable switch contact, a spring for moving said switch lever toward the movable contact, a cam on said segment adapted to engage said switch lever and move the same away from said stationary contact, 1

a holding device for holding the switch lever away from said stationary contact, including a detent lever having a catch arm provided with a hook adapted to engage a shoulder on the switch lever and retain the same in its retracted position and also having a releasing arm, a spring for turning the detent lever in the direction for engaging its hook with said switch arm, and a cam on the intermediate gear wheel adapted to engage said releasing arm and disengage said hook from said switch lever.

JOHN A. ELMES. 

